Basic tabbed list functionality.

Rob / Hugh - Here is my tabbed list enhancement in basic working form for you to test.

To Do:
Show active tab by comparing URL against this URL.
Provide menu functionality to add URL filters.

If you feel it is needed, I can add some functionality to optimise the tab reduction code to merge tabs with small no's of records first time through. The user should ideally provide a tab field which is close to the number of tabs to display so that tab reduction is not too iterative, but if they don't them this could be useful.